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authorAndy Lutomirski <luto@kernel.org>2018-01-31 08:03:10 -0800
committerIngo Molnar <mingo@kernel.org>2018-02-15 01:15:52 +0100
commit1299ef1d8870d2d9f09a5aadf2f8b2c887c2d033 (patch)
treecc25cd25eb5b5fa4844a951c8bd04a79abc5f80b /arch/x86/include
parentea00f301285ea2f07393678cd2b6057878320c9d (diff)
x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]()
flush_tlb_single() and flush_tlb_one() sound almost identical, but they really mean "flush one user translation" and "flush one kernel translation". Rename them to flush_tlb_one_user() and flush_tlb_one_kernel() to make the semantics more obvious. [ I was looking at some PTI-related code, and the flush-one-address code is unnecessarily hard to understand because the names of the helpers are uninformative. This came up during PTI review, but no one got around to doing it. ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Hugh Dickins <hughd@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linux-MM <linux-mm@kvack.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/3303b02e3c3d049dc5235d5651e0ae6d29a34354.1517414378.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/paravirt.h4
-rw-r--r--arch/x86/include/asm/paravirt_types.h2
-rw-r--r--arch/x86/include/asm/pgtable_32.h2
-rw-r--r--arch/x86/include/asm/tlbflush.h27
4 files changed, 24 insertions, 11 deletions
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 892df375b615..554841fab717 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -297,9 +297,9 @@ static inline void __flush_tlb_global(void)
{
PVOP_VCALL0(pv_mmu_ops.flush_tlb_kernel);
}
-static inline void __flush_tlb_single(unsigned long addr)
+static inline void __flush_tlb_one_user(unsigned long addr)
{
- PVOP_VCALL1(pv_mmu_ops.flush_tlb_single, addr);
+ PVOP_VCALL1(pv_mmu_ops.flush_tlb_one_user, addr);
}
static inline void flush_tlb_others(const struct cpumask *cpumask,
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 6ec54d01972d..f624f1f10316 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -217,7 +217,7 @@ struct pv_mmu_ops {
/* TLB operations */
void (*flush_tlb_user)(void);
void (*flush_tlb_kernel)(void);
- void (*flush_tlb_single)(unsigned long addr);
+ void (*flush_tlb_one_user)(unsigned long addr);
void (*flush_tlb_others)(const struct cpumask *cpus,
const struct flush_tlb_info *info);
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index e67c0620aec2..e55466760ff8 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -61,7 +61,7 @@ void paging_init(void);
#define kpte_clear_flush(ptep, vaddr) \
do { \
pte_clear(&init_mm, (vaddr), (ptep)); \
- __flush_tlb_one((vaddr)); \
+ __flush_tlb_one_kernel((vaddr)); \
} while (0)
#endif /* !__ASSEMBLY__ */
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 2b8f18ca5874..84137c22fdfa 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -140,7 +140,7 @@ static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid)
#else
#define __flush_tlb() __native_flush_tlb()
#define __flush_tlb_global() __native_flush_tlb_global()
-#define __flush_tlb_single(addr) __native_flush_tlb_single(addr)
+#define __flush_tlb_one_user(addr) __native_flush_tlb_one_user(addr)
#endif
static inline bool tlb_defer_switch_to_init_mm(void)
@@ -400,7 +400,7 @@ static inline void __native_flush_tlb_global(void)
/*
* flush one page in the user mapping
*/
-static inline void __native_flush_tlb_single(unsigned long addr)
+static inline void __native_flush_tlb_one_user(unsigned long addr)
{
u32 loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
@@ -437,18 +437,31 @@ static inline void __flush_tlb_all(void)
/*
* flush one page in the kernel mapping
*/
-static inline void __flush_tlb_one(unsigned long addr)
+static inline void __flush_tlb_one_kernel(unsigned long addr)
{
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
- __flush_tlb_single(addr);
+
+ /*
+ * If PTI is off, then __flush_tlb_one_user() is just INVLPG or its
+ * paravirt equivalent. Even with PCID, this is sufficient: we only
+ * use PCID if we also use global PTEs for the kernel mapping, and
+ * INVLPG flushes global translations across all address spaces.
+ *
+ * If PTI is on, then the kernel is mapped with non-global PTEs, and
+ * __flush_tlb_one_user() will flush the given address for the current
+ * kernel address space and for its usermode counterpart, but it does
+ * not flush it for other address spaces.
+ */
+ __flush_tlb_one_user(addr);
if (!static_cpu_has(X86_FEATURE_PTI))
return;
/*
- * __flush_tlb_single() will have cleared the TLB entry for this ASID,
- * but since kernel space is replicated across all, we must also
- * invalidate all others.
+ * See above. We need to propagate the flush to all other address
+ * spaces. In principle, we only need to propagate it to kernelmode
+ * address spaces, but the extra bookkeeping we would need is not
+ * worth it.
*/
invalidate_other_asid();
}